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Fifth Meeting of the Broadband Fixed Wireless Access Technical Sub-Group Held at Wyndham House on 16th June 2000 |
Those present:
Barry Lewis Chairman RA
Jim Nixon RA
Peter Jessup RA (acting secretary)
List of all those present in Annex A
IMPORTANT NOTE:
See Section 6, regarding the date of the next meeting.
1. Apologies
2. Agenda
Mr Lewis remarked that the paper to be presented under Item 5 "CEPT SE19: 40GHz Freq. Plans Update" was a working document for information to BFWAtg members and hence would not appear as a formal input to the meeting.
In response to a query from a BFWAtg member , Mr Lewis confirmed that an update to the CEPT SE19 28GHz work would be presented under Item 5.
3. Minutes of the fourth meeting BFWAtg(00)37
A BFWAtg member requested a minor amendment to Annex A to correct the name of his organisation to "Cable & Wireless".
In response to a question from a BFWAtg member on Section 2.3 "Guard Band Issues", Mr Lewis confirmed that the current Agency position was to use the potential "extra" 56 MHz pair of channels to insert 28 MHz guard bands between the proposed 112 MHz paired blocks of spectrum.
Regarding Section 5.1, a BFWAtg member clarified that the ISOP approach was not a "counter proposal" to the IA approach, but that ISOP could be derived from IA. However, there were still some differences to be resolved within CEPT SE19 between the two approaches as the ISOP approach did not provide consistent answers when given the same inputs as the IA calculation.
3.1 Matters Arising
Section 2.2: 3G Approach to Guard Bands for mobile operators - Mr Lewis remarked that this action was still on-going. The information was still awaited from the 3G Auction Team.
Section 2.5: 40GHz Issues – Mr Lewis remarked that this item would be addressed under Item 5 of the agenda.
Section 3.0: Adjacent Region Co-ordination – Mr Lewis stated that the analysis of ITU-R Rec. 452-9 regarding "percentage time" of interference was still outstanding. He added that the co-ordination flowchart still required to be updated to include members comments from the fourth meeting. Action B.Lewis
Section 4.0: Co-existence Issues – A BFWAtg member stated that he had received no comments on his presentation to the last meeting.
Section 5.2: P-P Links in Band – Mr Nixon remarked that he intended that the issues raised at the last meeting would be addressed at the sixth meeting. Action J.Nixon
4. Adjacent Region Co-ordination BFWAtg(00)39 (Powerpoint Presentation - 77.5Kb)
A BFWAtg member presented the further work undertaken by Aegis resulting from comments on their original work presented in February [BFWAtg(00)03]. Three areas were considered: the effect of an I/N of -6 dB; varying the antenna downtilts on PMP BSs; and different PMP cell sectorisation.
4.1 Effect of an I/N of -6 dB
The general conclusions of the work indicated:
For the reference base station, PFD limit at the service area boundary should not exceed:
95.5 dBW/MHz/m2 at 42 GHz
99.5 dBW/MHz/m2 at 28 GHz
And the respective co-ordination distances from boundary are:
13.5 km at 42 GHz
21 km at 28 GHz
In response to a question from a BFWAtg member, co-ordination is always required for distances less than 13.5/21 km (distance to boundary) regardless of terrain. With regard to subscriber station interference the co-ordination distances are line of sight, with no terrain.
A BFWAtg member remarked that the PDF limits were derived from LOS and this was not always the worst case. He added that signal enhancements, such as phase addition of signals, has not been taken into account.
A BFWAtg member clarified that the subscriber station interference analysis was based on subscriber-BS and subscriber-subscriber and that subscriber-BS dominated.
Mr Lewis asked for the opinion of planning using a I/N of -6 dB or -10 dB. Mr King said intra-system interference shall be the dominant factor. A BFWAtg member supports using a I/N of –6 dB. Mr Lewis said that he would check the ITU to report back their recommended limits. Action B.Lewis
A BFWAtg member commented that the cross polarisation figures used in the analysis, and given in ETSI, are optimistic since they do not consider physical alignment (installation), scatter and degradation over time.
In response to a question from a BFWAtg member, the 5-km limit applies to any station for co-channel, co-polar operation.
4.2 Varying the Antenna Downtilts
In this study, the BS antenna down tilt was varied between 0 and 9 degrees. A Monte Carlo statistical analysis was conducted to determine the impact of different down tilts on interference environment.
A BFWAtg member said the results of the study show that interference from multiple PMP BS interferers operating in adjacent geographic area will be within the desired limits providing the BS antenna downtilt is not less than 8 degrees. He added that using different antenna RPE may have an impact on the conclusions.
4.3 Different PMP cell sectorisation
30°, 60°, 90° and 120° PMP cell sector widths were modelled. The Tx power was adjusted to maintain the EIRP level. The statistical analysis confirmed that:
- There is a higher probability of suffering interference from PMP BS in adjacent geographic areas if wider sector cells are deployed
- The highest probable interference levels for different sector widths deployed do not differ significantly
Hence, providing the co-ordination requirements are satisfied, the interference levels experienced by adjacent geographic region BFWA station will be acceptable regardless of the PMP cell sector width deployed
A BFWAtg member commented that ETSI TS1 antenna is very poor and that, potentially, better antennas could lead to more received interfering power and this would impact on the analysis.
Mr Lewis said the Aegis report will be approved within 2-3 weeks. This report shall be made available on the website for further comments on C/I.
5. 40 GHz WRC Issues BFWAtg(00)38
Mr Lewis presented BFWAtg (00)38. Mr Lewis remarked that the WRC had made an allocation to the Fixed Satellite Service (FSS) [also retaining Broadcasting Satellite Service (BSS)] in Region 1 in the band 40.5 to 42.5 GHz. Mr Lewis also highlighted that under new footnote S5.547 the band 40.5 to 43.5 GHz was now identified as a band available for High-Density Fixed Service (HDFS) applications.
A BFWAtg member asked what was the UK position with regard to the use of FSS (Earth to space) in 42.5 to 43.5 GHz. Mr Lewis replied that he understood that there had been some work on this during the last study period.
Action: Mr Lewis to provide information to meeting members on the UK position on the use of FSS (Eà s) in 42.5 to 43.5 GHz..
Mr Lewis highlighted the new additions to Appendix S21 that introduced new Power Flux Density (pfd) limits on the space-borne FSS transmitters. These were consistent with those developed during the last study period leading up to WRC 2000 to protect the Fixed Service.
Mr Lewis highlighted the future work under COM5/28 "Power flux-density limits in the bands 37.5-42.5GHs for the FSS, BSS [and mobile-satellite service]":
- Notwithstanding the limits in Table S21-4, studies are invited on whether the pfd values adequately protect FS in the bands [37.5-40GHz,] 40.5-42GHz and 42-42.5GHz from space-borne transmitters;
- To study pfd values for the BSS in the range 40.5-42.5GHz;
- To address the criteria and techniques for addressing interference into FSS receivers from FS transmitters intended to operate in the same area;
- To study the nominal clear-sky pfd’s and time percentages that they might be exceeded to cater for fading conditions between satellites and earth stations.
Regarding future work under COM5/27 "Development of the technical basis for co-ordination of radio astronomy stations with transmitting high-density fixed systems in the fixed service, in the band 42.5-43.5GHz", Mr Lewis remarked that the Agency had already initiated its own work to study the protection criteria for radio astronomy stations in the UK.
Action: Mr Lewis agreed to provide the meeting members with the full text of the resolutions COM5/27 and COM5/28.
6. CEPT PT SE19: Frequency Plans Update
6.1 40 GHz Issues Temp. BFWAtg(00)xx
Mr Lewis discussed temporary document BFWAtg(00)xx which was provided for information. It was generally accepted that a traditional FS plan was not viable in this band. He introduced the four proposed options and their advantages and disadvantages. He stressed that these were not put forward as solutions, but rather to stimulate discussion within SE 19 on the guidelines for administrations to plan the band given particular scenarios. During the discussion the following salient points were raised:
- Any plan needs to be able to support both symmetrical and asymmetrical systems;
- Any plan needs to accommodate FDD and TDD systems;
- Asymmetric traffic does not necessarily require asymmetric spectrum;
- Not allocating all the spectrum in the first instance allows flexibility in the future in assigning spectrum for network, and traffic profile, developments.
In discussing traffic asymmetry a BFWAtg member remarked that video streaming is highly asymmetric with a large downstream and this is also true for data to a single customer premise equipment (CPE). However, when considering a CPE that is a (business) LAN then the data traffic could be symmetric or evenly highly asymmetric with a large upstream. This suggests that systems may need to be dynamic to cope with such variances in CPE requirements, and he added that TDD is ideally suited to this.
6.2 26/28 GHz Issues
A BFWAtg member reported that the executive summary to the guidelines report [SE19 (99) 195 rev 8] had been drafted and he was in correspondence with the report editor with regard to finalising the co-ordination separation distances to be included in the report.
He added that there were "place holders" in the main body of the report in order to include text on the IA approach and he expected to make contribution to the next PT SE19 meeting on 4 – 6 July ’00 on this issue. He also restated that it was the aim to resolve the differences between the ISOP and IA calculations, in order to give consistent results, during the next meeting.
It was noted that there was a CEPT WG SE meeting 14 – 18 June ’00 where the status of the report would be presented.
1. AoB
Mr Lewis remarked that information had been received that the Norwegian Post and Telecoms had recently awarded three licences at 40 GHz, of 500 MHz each, to Telenor, Tele2 and OBOS/NBBL with no specific frequency plan pending the resolution of issues within CEPT.
2. DONM
The sixth meeting will be held on Wednesday 26th July ’00 at Wyndham House.
PLEASE NOTE: Due to the unavailability of a meeting room in Wyndham House regrettably it is necessary to re-schedule the next meeting to 2nd August at 10:30.
Top
Organisation
Contact
Aegis Systems Ltd
Zoran Spasojević
BT
Paul Grant
BWA
John R Norbury
Cable and Wireless
Tom King
First Mark Communications
Roy Titchmarsh
First Mark Communications
Mike Godfrey
Harris Systems Ltd
Gerry Gerrard
Kingston Communications
Mike Crowther
Orange
Robin Whithard
Radiant Networks PLC
Phil Whitehead
RAL
Mike Willis
RAL
J Biddiscombe
Telia
Alan Penney
TTP Communications
John Haine
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